That can happen during the flowering stretch, yes. It's a nitrogen deficiency, but no problem.
The plant has cannibalized itself, as mentioned, to keep the upper parts healthy.
I wouldn't worry about it, just trim the leaves if they die off.
There's not much you can do since your plant mainly needs phosphorus and potassium in the next few days, so there's no point in feeding it again now.
Just enjoy that the rest is healthy, the leaves are unnecessary anyway👌
Have a relaxed weekend, feel free to message me privately if you want. Bottom right👍